create an upgrade test for a nine beta version

master/buildbot/test/integration/test_upgrade.py

@@ -203,6 +203,16 @@ def test_emptydb_modelmatches(self):
         return d
 
 
+class UpgradeTestV090b4(UpgradeTestMixin, unittest.TestCase):
+
+    source_tarball = "v090b4.tgz"
+
+    def test_upgrade(self):
+        return self.do_test_upgrade()
+
+    def verify_thd(self, conn):
+        pass
+
 class UpgradeTestV087p1(UpgradeTestMixin, unittest.TestCase):
 
     source_tarball = "v087p1.tgz"
@@ -220,6 +230,4 @@ def assertModelMatches(self):
         pass
 
     def test_upgrade(self):
-        # we no longer need a builder pickle since the builder can be
-        # re-created without one
         return self.do_test_upgrade()

master/buildbot/test/integration/v090b4-README.txt

@@ -0,0 +1,5 @@
+-- Basic v0.9.0b4 tarball --
+
+This tarball is the result of a couple of runs from a single
+incarnation of a master that was running Buildbot-0.9.0b4.  Both
+builds were successful.